1. Field
Embodiments disclosed herein generally relate to a thermally assisted magnetic recording head and a magnetic recording device provided therewith for use in a hard disk drive.
2. Description of the Related Art
Areal recording densities for magnetic recording devices continue to increase requiring the size of the magnetic bits in the recording media of these devices to become increasingly smaller and more compact. In conventional magnetic recording devices, a greater recording density was achieved by reducing the size and spacing of the magnetic grains (bits) for the magnetic recording media along with shrinking the magnetic recording head for writing the bits. Due to heat fluctuations in the magnetic recording devices, the magnetic information recorded in the media may be lost over a short period of time. This loss of recorded magnetic information may occur at room temperatures in recording media which has an areal recording density in excess of 1 Tbit/inch2. In order to prevent the loss of the recorded magnetic information, a coercive force (coercivity) may be raised for the magnetic recording media. The coercivity is the intensity of the applied magnetic field. However, there are limits to the magnitude of the magnetic field that can be generated from the magnetic recording head. Forming recording bits on the magnetic media becomes difficult if the coercive force increases too much.
In recent years, the industry has turned to a method of thermally assisted magnetic recording. In this method, the coercivity is lowered by heating the media while recording onto the recording media. Thermally assisted magnetic recording achieves a high recording density by locally heating the recording media, i.e. restricting the heat solely to the recording region. The heating of the recording media is performed by a minute light spot generated at a high power density. In a conventional thermally assisted magnetic recording head, a lens is used to generate the minute light spot. The lens adds additional weight to the thermally assisted magnetic recording head.
Increasing areal recording densities for the recording media have resulted in a decrease of the distance (gap) between the magnetic recording head and the magnetic recording media. The magnetic recording head is elevated off the recording media surface by a cushion of air as the disk spins. As the gap between the magnetic write head and the magnetic recording media approaches 10 nm or less, the cushion of air is no longer capable of levitating, or supporting, the magnetic recording head off the magnetic recording media. The weight of the lens mounted on the magnetic recording head causes the magnetic recording head to come into contact with the magnetic recording media.
The magnetic recording device may support a plurality of magnetic recording media (discs) stacked within the magnetic recording device and the space between adjacent discs is typically less than 1 mm. Thus, a space the size of approximately 1 mm must support the gap along with the magnetic recording head and all the additional components supporting the magnetic recording head, i.e. support arm. As a result, optical elements, such as a lens, have become undesirable to mount to the magnetic recording head because the additional weight of the optical elements may cause the magnetic recording head to come into contact with the recording media and damage the magnetic recording device.
Therefore there is a need in the art for a thermally assisted magnetic recording head for use with increased areal recording densities.